1. Field
The present invention relates generally to wireless communications systems, and more specifically, to systems and methods for providing a tunable duplexer with a common node notch filter.
2. Background
Full-duplex radio transceivers are used in many mobile communication devices, such as cellular telephones. Such a transceiver includes a transmit path and a receive path that both share a common antenna. Systems are designed to avoid leakage of the transmit signals into the receive path and to avoid leakage of the receive signals into the transmit path.
Miniature, full-duplex radio transceivers are used in many cellular telephones. The transmit path and the receive path of the transceiver are both coupled by a duplexer to an antenna. The duplexer performs both transmit and receive filtering. The duplexer is designed to avoid leakage of the transmit signals into the receive path and to avoid leakage of the receive signals into the transmit path.
It is desirable to provide a duplexer that adequately filters the transmit and receive signals and that isolates the transmit and receive signals with a simple topology. Accordingly, benefits may be realized by providing an improved duplexer that filters the transmit and receive signals and that isolates the transmit and receive signals.